Switched-mode power converters are widely used in automotive, industrial, consumer electronics or information technology (IT) applications for converting an input voltage into an output voltage received by a load. In many applications, such as CPU (Central Processing Unit) powering applications, it is required to generate an output voltage with a relatively low level from a higher input voltage. For example, modern CPUs require a supply voltage with a voltage level of only 3V, 1.8V, or 1.2V. In this type of application a first power converter may convert a grid voltage (with 22VRMS or 110VRMS AC) into a first DC supply voltage with a level of, for example, 12V, and a second power converter transforms the first supply voltage into the low DC supply voltage required by the CPU.
Multi-phase converters include a plurality of converter units that are connected in parallel and that each provide a portion of the power consumption of the load. Each of the converter units includes at least one semiconductor switch that is operated in a pulse-width modulated (PWM) fashion. A PWM operation of the at least one semiconductor switch involves losses, wherein these losses, at a given output power of the converter unit, increase as the voltage blocking capability of the semiconductor switch increases. In a conventional multi-phase converter, the voltage blocking capability of the at least one switch in each converter unit is at least the difference between the input voltage and the output voltage of the multi-phase converter.